In recent years, the light emission efficiency of an LED (Light Emitting Diode) grows higher, which makes it possible to use an LED with reduced power consumption and prolonged lifespan as a light source of a lighting apparatus. There is proposed a lighting apparatus that includes electrode pins having the same shape as electrode pins of a fluorescent lamp standardized by JIS Standards so that the lighting apparatus can be used without having to modify an existing fluorescent lamp fixture. The lighting apparatus is configured to be turned on as electric power is supplied through the electrode pins thereto. For example, Japanese Patent Application Publication No. 2009-43447 discloses a configuration in which an LED substrate is held within a straight outer tubular body. Two metal caps to be mounted to an existing fixture for a straight-tube-type fluorescent lamp are provided at the opposite ends of the outer tubular body.
In such a conventional LED lamp stated above, one cap serves as a power feeding cap and the other cap serves as an earth cap. In a lighting apparatus using the LED lamp as a light source, as shown in FIG. 12, a power feeding socket (not shown) for reception of the power feeding cap and an earth socket 100 for reception of the earth cap are attached to an apparatus body 101.
In this regard, the earth socket 100 is provided therein with a conductor plate 102 with which a lamp pin (not shown) of the LED lamp makes contact. The conductor plate 102 needs to be earth-connected to the apparatus body 101. The earth socket 100 has a wire insertion hole 100A into which one end of a lead wire 103 can be inserted. The conductor plate 102 is provided with a quick-connection terminal portion (not shown) to which one end of the lead wire 103 inserted into the wire insertion hole 100A is connected. A crimp-type terminal 103A to be screw-fixed to the apparatus body 101 is provided at the other end of the lead wire 103.
Description will now be made on a method of earth-connecting the conductor plate 102 of the earth socket 100 to the apparatus body 101. First, one end of the lead wire 103 is inserted into the wire insertion hole 100A of the earth socket 100 and is connected to the quick-connection terminal portion of the conductor plate 102. Then, the crimp-type terminal 103A provided at the other end of the lead wire 103 is brought into contact with one surface of the apparatus body 101 and is screw-fixed to the apparatus body 101. This makes it possible to earth-connect the conductor plate 102 of the earth socket 100 to the apparatus body 101.
In the event that the conductor plate 102 of the earth socket 100 is earth-connected to the apparatus body 101 in the manner stated above, however, it is necessary to perform a task of screw-fixing the lead wire 103 to the apparatus body 101. In this case, the following problems are posed. The crimp-type terminal 103A needs to be formed at the tip end of the lead wire 103. The loosening of a screw has to be taken into account when screw-fixing the lead wire 103. Time and effort is required in arranging the lead wire 103. The assembling work (connection work) becomes laborious and cumbersome.